This invention relates to structural joints for connecting fiber-reinforced plastic beams or girders without strength reducing bolts, grooves, or the like. More particularly, the invention relates to a double I-beam (DIB) joint for connecting fiber-reinforced plastic beams or girders into civil engineering structures.
Prior uses of fiber-reinforced polymers or plastics and the like plastic structures are believed to be typified by patents such as the following: U.S. Pat. No. 3,100,555 describes a tower structure composed of tubular plastic structural members joined by segmented plastic joints which are glued together to interconnect the intersecting braces, legs, etc. U.S. Pat. No. 3,685,862 describes connectors for joining plastic rods within hoops in which the converging rod portions are squeezed together and held by driven-in wedges. U.S. Pat. No. 3,975,874 describes a prefabricated plastic swimming pool design which proposes side and shoulder portions supported by X-shaped molded plastic braces having I-beam cross-sections along some portions and flat cross-sections in other locations. U.S. Pat. No. 4,177,306 describes laminated plastic girders in which some of the fiber-reinforcing materials extend into both of the girders.